There are three principles for radiation protection: justification, optimization and dose limitation. ALARA means “As Low as Reasonably Achievable” and is a principle of optimization in radiation safety for diagnostic methods using ionizing radiation. This principle was created based on the linear hypothesis, which states that any level of radiation dose exposure could increase the risk of genetic mutations and cancer. Radiation safety campaigns promote mainly ALARA and state that all those involved in such diagnostic methods should follow this principle. This includes radiation safety staff, radiation safety committees, research faculty and all radiation workers.